Duplication and nonregistration of COVID‐19 systematic reviews: Bibliometric review

Abstract Objectives This study examines the conduct of systematic reviews during the early stages of the COVID‐19 pandemic, including compliance to protocol registration and duplication of reviews on similar topics. The methodological and reporting quality were also explored. Methods A cross‐sectional, bibliometric study was undertaken of all systematic review manuscripts on a COVID‐19 intervention published between January 1st and June 30th, 2020. Protocol registration on a publicly accessible database was recorded. Duplication was determined by systematically recording the number of reviews published on each topic of analysis. Methodological quality and reporting quality were assessed using the AMSTAR‐2 and PRISMA 2009 instruments, respectively. Results Thirty‐one eligible systematic reviews were identified during the inclusion period. The protocol of only four (12.9%) studies was registered on a publicly accessible database. Duplication was frequent, with 15 (48.4%) of the 31 included studies focusing on either hydroxychloroquine (and/or chloroquine) or corticosteroids. Only one study (3.2%) was of “high” methodological quality, four (12.9%) were “low” quality, and the remainder (n = 26, 83.9%) were of “critically low” quality. The median completeness of reporting was 20 out of 27 items (74.1%) with a range of 5–26 (interquartile range: 14–23). Conclusion Systematic reviews during the early stages of the COVID‐19 pandemic were uncommonly registered, frequently duplicated, and mostly of low methodological quality. In contrast, the reporting quality of manuscripts was generally good but varied substantially across published reports. There is a need for heightened stewardship of systematic review research, particularly during times of medical crisis where the generation of primary evidence may be rapid and unstable.


| Study design
This was a cross-sectional, bibliometric study of published systematic review manuscripts reporting primary interventional evidence in the context of COVID-19. For each review, protocol registration on a publicly accessible database was recorded and duplication was examined by assessing the number of reviews identified for each topic of analysis.
Methodological quality was assessed using the AMSTAR-2 checklist. 7 This is a widely used 16-item checklist used for methodological appraisal of systematic reviews and has been shown in previous studies to be reliable and valid. 8 Reporting quality was assessed according to compliance with the PRISMA 2009 checklist, 9 which is a reporting checklist endorsed by the EQUATOR network and universally accepted by journals responsible for publishing healthcare research. The citation rate of each manuscript was also explored.
A systematic review of primary interventional evidence was defined as a review assessing the benefits or harms of preventative or therapeutic interventions used in healthcare. This may or may not include a statistical meta-analysis.

| Search strategy
Potentially eligible systematic reviews were identified by performing a systematic search of MEDLINE and EMBASE (via OvidSP). This was performed using the search terms shown in Table 1 and was undertaken by a single investigator on June 30th, 2020. Time limits for this search were set between January 1st and June 30th, 2020. The results were saved offline, and any duplicates were removed. Two independent investigators screened titles, abstracts, and full texts for possible inclusion (Jack A. Helliwell

| Eligibility criteria
To be eligible for inclusion, studies were required to be a systematic review or a scoping review with a systematic search and have subject material focusing on an intervention (prevention or treatment) in the context of COVID-19. Original research articles presenting primary data were excluded, as were editorials and gray literature (conference extracts and other nonpeer-reviewed work). Articles published in non-English languages were also excluded since resources to translate these were not available.

| Study outcomes
Registration and duplication of review topics were explored. Registration at any time was assessed by examining manuscripts for a unique registry identifier. Where no identifier was found, the PROSPERO database was manually searched. This is a widely used, international database of registered systematic reviews with a health-related outcome. It was assumed that the absence of an identifier and no record on the PROS-PERO database indicated the absence of registration. To assess duplication of research topics, a qualitative consensus process was undertaken in which the scope and final study inclusion of each review were examined and thematically defined by two independent investigators (Jack A. Helliwell and Joe Thompson), with referral to a third investigator for disagreements (Stephen J. Chapman). Other outcomes of interest were methodological and reporting quality of manuscripts. Methodological quality was assessed using the AMSTAR-2 checklist, which provides an assessment of "critical" and "non-critical" weaknesses along with an overall measure of "confidence" ( Table 2). 7 Completeness of reporting was assessed using the 27-item PRISMA 2009 checklist. 9 The presence of each item was recorded and reviews were assigned a score out of 27.
Items that were not applicable (i.e., relating to meta-analysis only) were assigned a positive score by default to preserve comparability. Finally, the citation history of each manuscript was collected through Google Scholar (https://scholar.google.com) to explore the impact of each review.

| Demographics
A total of 662 studies were identified from the initial search. Of these, 26 were eligible for inclusion, with another 5 identified from a review of references. A total of 31 studies were eligible for analysis ( Figure 1). A list of included studies is available in Table S1. The majority of reviews were performed in the United Kingdom (n = 9, 29.0%) and the United States (n = 8, 25.8%). Twelve (38.7%) included a statistical meta-analysis. All but one study focused on a therapeutic treatment (n = 30, 96.8%) with the other remaining study focusing on prevention. The most common interventions were hydroxychloroquine and/or chloroquine (n = 10, 32.3%), corticosteroids (n = 5, 16.1%), and antiviral therapies (n = 3, 9.7%) ( Table 3).

| Registration
Protocol registration on a publicly accessible database was disclosed in 4 out of 31 studies (12.9%). The databases used included: PROS-PERO (n = 2), Centre of Open Science (n = 1), and ResearchRegistry (n = 1). A further three studies included information about a review protocol within the methods section of the manuscript but did not provide detail as to whether this was available publicly before the completion of the study. Two studies reported that a protocol had not been registered due to the urgency of the public health crisis.

| Duplication
Fifteen (48.4%) out of the 31 included studies focused on either hydroxychloroquine (and/or chloroquine) or corticosteroids as treatment options for COVID-19 (Table 3). There was a total of

| Completeness of reporting
The median completeness of reporting across 31 included studies was 20 out of 27 items (74.1%) with a range of 5-26 (IQR: 14-23). Compliance with individual items was variable (

| Citations
Of the 31 included studies, the median total number of citations was 109, with a range of 23-974 (IQR: 67-161). The median citation rate per month was 8, with a range of 2-70 (IQR: 6-13) ( Table 3). collaboration. 13 Mandatory registration on such platforms (as is the case for clinical trials) may be one means of increasing registration uptake.

| Strengths and weaknesses of the study
Strengths of this study are recognized. The results provide a unique perspective on an existing problem that is evidently exaggerated during  6 While this is in contrast to the present study, the principles and key take-home messages generated by this study are considered to be transferable. Lastly, it is notable that only English language reviews were included in this study due to the unavailability of translation sources. It is possible that the results underrepresent the extent of the problem since reviews in other non-English are likely to exist but were not included in the present analysis.

| CONCLUSION
In conclusion, this review identifies a modifiable problem relating to the conduct of systematic review research during a public health crisis and demonstrates the need for heightened stewardship to ensure only the best evidence informs clinical practice. It highlights particular issues relating to low levels of review protocol registration and high levels of duplication in published reports of systematic reviews. These results add further support for the registration of systematic reviews using open-access platforms such as PROSPERO.
The results should also guide editorial teams during their review and decision-making processes in times of public health crises. Particular attention should be given to the justification for systematic reviews, particularly in settings where the primary evidence is likely to be highly unstable and rapidly superseded.

CONFLICTS OF INTEREST
The authors declare no conflicts of interest.

AUTHOR CONTRIBUTIONS
Stephen J. Chapman and Neil Smart conceptualized the study. Jack A.
Helliwell and Joe Thompson performed searches and extracted data, which were verified by Stephen J. Chapman. Jack A. Helliwell prepared the initial manuscript draft, which was subsequently edited by all authors. All authors agreed to the submission. Stephen J. Chapman is the study guarantor.

DATA AVAILABILITY STATEMENT
Data are available upon reasonable request.